Alpine 7807 Head Unit and 3801 Amp

I am totally new to this forum, so be gentle.   I just purchased a 1989 Mercedes wagon...in it is an Alpine 7807 head set and 3801 amp... 1. Are these decent units to play around with? 2.The lights on the face plate (radio station info) do not work...how would I get a new faceplate? 3. The speakers are the originals...how do I find out what would be best to replace them with?  4. On Mercedes, there is a fader dial on the console...thus, you run tow speakers to the fader, this breaks it up the the front and rear...rather than independently running separate 4 speakers from the amp...As I see it, the previous owner took the front speaker outputs and ran them to the fader, then let the fader divide front and rear...this sounds like a lot of sound could get lost in that dinky fader switch...should I bypass it?      Thanks for any help....Alan

yes alpine is good......you can find out what kind of speakers you need by going eitherr 2 crutchfield.com or sounddomain.com and inputting your carinfo ...but dont buy from these places thats about all i can help you wit

You can try to find parts for these older Alpine units from here: https://www.pacparts.com/alpine/default.cfm

If you are adding new speakers to the car, the best bet is to remove the speakers and find out what size they are. Go to your local audio store and bring in a CD that your familiar with and test speakers on the board to see what sounds the best for your ears.